WASHINGTON -- The justices of the U.S. Supreme Court asked no questions about the president's pardon authority or Robert Mueller on Thursday during oral arguments in a case that experts said could affect the special counsel's Russia probe.
The justices heard arguments from Terance Gamble, an Alabama man contesting his dual sentencing by state and federal courts for unlawfully possessing a firearm as a felon.
The case concerns the so-called "dual sovereignty" exception to the Constitution's Double Jeopardy clause. Legal experts suggested that overturning the doctrine could increase the president's pardon authority.
Experts said before the case was argued that if Gamble was successful, it could hinder state efforts to prosecute Mueller's targets if any receive a pardon for federal offenses. One top Supreme Court lawyer joked to The Washington Post that the case should be called Manafort v. Mueller.
But the justices did not raise that issue, focusing largely on whether the case could limit American courts' ability to prosecute offenses that have already been raised in foreign courts.
While the 5th Amendment says that no person can be put in jeopardy two times for the "same offence," the Supreme Court has held for at least 150 years that it is permissible for someone to be charged with the same crime by a state and the federal government.
Two years ago, Justices Ruth Bader Ginsburg and Clarence Thomas, who sit on opposite sides of the ideological spectrum, suggested that doctrine needed to be revisited. In Terance Gamble v. United States, No. 17-646, the court did just that.
As the nonpartisan Congressional Research Service found in an August report, a decision scrapping the dual sovereignty exception could "indirectly strengthen the President's pardon power, by precluding a state from prosecuting an already-pardoned defendant who has gone to trial on an overlapping offense."
The president has not ruled out a pardon for his former campaign chairman Paul Manafort, who was convicted on a slew of financial charges in Virginia over the summer. In September, Manafort pleaded guilty to more federal crimes in Washington.
But, if state prosecutors are set on prosecuting Manafort, or any other Trump associate, it's not clear that the case could have that dramatic an impact.
That's because in many states, including Virginia and New York, state laws already prevent dual prosecution for the same crime.
Legal scholars have also suggested that Mueller has strategically avoided bringing certain charges in order to leave them for the states, should they want to proceed with them.
Regardless of its impact on Mueller, the case will be significant for Terance Gamble, who could face three extra years in prison if the court rules against him.
In 2015, Gamble, who had been convicted years before on a felony robbery charge, was pulled over by a police officer in Alabama for a broken headlight. That led to the discovery of a pistol in Gamble's vehicle, unlawful for a felon under both state and federal law.
Gamble pleaded guilty to a state court in Alabama and was sentenced to a year in prison. Shortly after, a federal court sentenced him to 46 months for the same crime. Gamble contested the second charge on the basis of his protection from facing double jeopardy, but his case was dismissed by a district court, and later his conviction was affirmed by the 11th U.S. Circuit Court of Appeals.
In its decision, the 11th Circuit found that the "Supreme Court has determined that prosecution in federal and state court for the same conduct does not violate the Double Jeopardy Clause because the state and federal governments are separate sovereigns."
Barring a ruling overturning that precedent, Gamble, 29, will not be released from prison until February 2020.
After more than an hour of argument it was not clear which side would be able to muster a majority. A ruling is expected by late June.